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 As connected devices multiply in the home, from set-top boxes, smartphones, and computers, to Internet of Things (IoT) gadgets and monitors, there’s concern that there will be a corresponding increase in overall energy used by these myriad network interfaces. Instead, these network interfaces are actually the key to reducing total energy in the household by consolidating resources and notifying when resources are needed or can be placed in a lower power state or turned off.

The concerns are being addressed by new device interface standards and protocols that are combining with technologies such as the IoT and working together in the background to make usage-aware decisions that minimize energy used while also ensuring the expected – or even improved -- user experience.

In June of 2014, the Consumer Electronics Association released a study it had commissioned that showed consumer electronics consuming 12% of the average household power budget, with most of that going to TVs (30%), set-top boxes, and PCs, followed by gaming consoles and network equipment, such as routers (Figure 1).

Figure 1. Consumer electronics consumed 12% of the average yearly home power budget in 2013. Streaming OTT video services have the potential to increase that percentage, but new technologies can tightly control the power consumed. (Image courtesy of the Consumer Electronics Association)

In the two years since then, streaming video has taken off with over-the-top (OTT) streaming services spreading from TVs and STBs, to tablets and smartphones. Juniper Research estimated in May this year that globally, subscriber numbers to OTT services such as Netflix and Amazon Prime will increase from 92.1 million in 2014, to 332.2 million by 2019.

While OTT services have traditionally been viewed by the consumer using devices such as Chromecast, Roku, AppleTV, Fire TV Stick, and gaming consoles, STBs will also be platform of choice as operators get involved in delivering OTT services.

This convergence of interest around streaming video, from third-party OTT content distribution enablers to users and now operators, combined with increasingly stringent power requirements for service gateways, led service providers, consumer electronics companies and technology suppliers to work together to improve service to the end user across the many standards and interfaces (Figure 2.). One of the more exciting developments to come out of this cooperation is DLNA’s VidiPath which helps tie together the network power saving features from lower layers.

Among other things, including the seamless delivery of OTT and subscription services to any device, VidiPath works with open standards such as IEEE 1905 nVoy for power modes across device, link and service layers, to enable the lower power state for a given device based on its content needs and usage patterns.

Figure 2. An illustration showing the relationship of the different network layer standards. At the application layer, a VidiPath application is able to manage functions and services across the networked home to enable minimizing overall energy use.

At the device level, technology advances such as full-band capture have already enabled the integration of the equivalent of multiple tuners on a STB. Combined with communications networks in the home, this has allowed a single device to consolidate and serve tuner resources to multiple tuner-less clients, greatly reducing the overall power consumption.

VidiPath goes deeper into a STB by integrating an STB’s system-on-chip (SoC) modular power states. The SoC typically has four power states that can be actively managed, all of which balance features with power (Figure 3.) The states range from S0 (ON) with all features available and maximum power consumption, to S3 (Deep Standby) with no features available and almost no power being consumed.

Figure 3. A typical STB SoC has four power states, each of which look for the optimum balance of available features and power consumption, based on device usage.

S3 is an extreme case, as it breaks network connectivity and is generally not used. S2 (Low Latency Standby) at least allows the device to be awoken by the network, which is critical for network-based power management.

At the link layer, it’s true that Energy Efficient Ethernet (EEE) is a part of the whole Home Networking connectivity solution, but in reality, most homes don’t have Ethernet (CAT 5 or 6) between rooms, and even when present, it’s often not in a convenient location.

As a result, most service providers end up deploying “no new wires” networking technologies such as HomePlugAV over electrical mains, MoCA over TV, cable or satellite coaxial cabling, or over Wi-Fi (no wires).

This hybrid networking model was the impetus behind IEEE 1905.1 nVoy, which defines an abstraction layer that provides a common interface for the most compelling and deployed home networking technologies in the market (Figure 4.)

Figure 4. IEEE 1905.1 defines an abstraction layer that allows control of devices in a hybrid network in order to optimize data routing and interface status for maximum throughput at minimum power.

Among other things, IEEE 1905.1 enables enhanced datapath selection, as well as enhanced power management by using the most efficient interface, turning off unnecessary interfaces, and turning on interfaces only when needed.

It’s worth noting that other network technologies are supported by an extensible mechanism using an IEEE OUI and XML formatted document; so this is widely scalable in the communication industry.

DLNA/UPnP Network Power Signaling

As mentioned earlier, a device without a network connection is not much use in a network-based power-control paradigm, so it is assumed that for network power signaling that even when power saving, network communications must be maintained.

Two other assumptions are made, the first being that device services and interfaces are modular: some functional blocks inside a physical device can be awake, while others are asleep.

The second assumption is that the internal power controller makes all decisions about how to manage its resources within a physical device. This is important as an external requesting device cannot really know the details of another physical device. Also, multiple clients will have unique requests.

These are the assumptions upon which the Digital Living Network Alliance (DLNA) Low Power / UPnP Forum EnergyManagement:1 Service is based. The Service includes Service Subscription, which allows clients to indicate which resources are needed from a server and a server can make informed choices on how to reduce its power while limiting disruption to the clients that depend on it, (Figure 5.)

Figure 5. DLNA Low Power / UPnP Energy Management: 1Service allows control of services, power saving modes, and discoverability of a server device by client devices, even if its network interfaces are non active, using a proxy.

The Service also includes WakeOnPatterns, which allows a device to advertise on the network the specifics of signaling required to change its network interface state, as well as Proxied Network Interface Information.  This allows a server device to be immediately discoverable by client devices, even if the server device’s network interfaces are currently non-active.

The IoT Effect

As these standards and protocols were being actively developed in close collaboration across the ecosystem, an interesting technological phenomenon called the Internet of Things (IoT) is taking off, almost organically.

At a basic level, IoT-enabled devices are used to monitor or control devices from a remote location using a network connection. From there, data analysis is added at some level, typically the gateway, to identify trends and improve the usability benefits of the device.

While it might again seem that adding IoT-enabled devices would again add to the energy problem with a multitude of devices gathering and communicating data, typically over a wireless interface such as Bluetooth, Wi-Fi or ZigBee. That’s not necessarily the case.

For one, the manufacturers of the devices are compelled to keep the power consumption as low as possible as these devices are typically battery powered. This requires not only ultra-low-power silicon, but also the incorporation of various sleep modes and smart use of transmit/receive up time.

At a higher level, this naturally evolving network of devices complements the work done at the device, link and services layers by adding more sensing and ambient intelligence to the power-saving network.

For example, using IoT it’s been clearly shown how users can remotely turn specific devices off or on using a smartphone or remote computing device. However, using connected sensors within the home, the network can now tell when a user leaves a space while watching a show and can migrate that show to a nearby device, while putting the first device on standby. Or in another use-case scenario, the hot water for a shower or coffee can be heated just as the user stirs from sleep, instead of keep the water hot at all times.

These are a few fairly simplistic examples, some of which have already been demonstrated at CES 2015, but it’s the beginning of the fusion of intelligent networking protocols and IoT that can almost “consciously” reduce overall power consumption unbeknownst to the user, while simultaneously enhancing that user’s experience.

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